Semiconductor processing apparatus for promoting heat transfer between isolated volumes

Abstract

Apparatus for promoting heat transfer between a first volume (chamber volume) and a second volume (expandable, substrate support platform volume). Specifically, the apparatus comprises: a chamber defining a chamber volume that contains a chamber atmosphere, e.g., a partial vacuum; a substrate support platform that defines an expandable volume that contains a heat transfer medium, e.g., air; and a seal that isolates the chamber volume from the heat transfer medium. The substrate support platform further comprises: a substrate support platen that has a first surface located within the chamber volume and a second surface located within the expandable volume; a housing sealed to the second surface of the substrate support platen; and a expandable member such as a bellows, attached to the housing, to provide for expansion of the expandable volume that is defined by the housing and the bellows. The housing is typically fabricated of metal and the substrate support is typically fabricated of ceramic. The seal forms a hermetic junction between the ceramic substrate support and the metal housing.

What is claimed is: 
     
       1. Apparatus for promoting heat transfer comprising: a chamber defining a chamber volume containing a chamber atmosphere;   an expandable volume containing a heat transfer medium; and   sealing means, located between the expandable volume and the chamber volume, for isolating the heat transfer medium from the chamber atmosphere.   
     
     
       2. The apparatus of claim 1 wherein the expandable volume comprises: a substrate support platen having a first surface within said chamber volume and a second surface within said expandable volume;   means, attached to said second surface of said substrate support platen, for retaining said heat transfer medium proximate said second surface of said substrate support platen; and   an expandable member located between said retaining means and a source of the heat transfer medium.   
     
     
       3. The apparatus of claim 2 wherein said expandable member is a bellows. 
     
     
       4. The apparatus of claim 2 wherein said sealing means is attached between said retaining means and said second surface of said substrate support platen. 
     
     
       5. The apparatus of claim 4 wherein said sealing means is a metal strip that is brazed along one edge to a flange extending from the second surface of said substrate support platen and brazed along a second edge to said retaining means. 
     
     
       6. The apparatus of claim 4 wherein said retaining means is fabricated of metal and said second surface of said substrate support platen is fabricated of ceramic. 
     
     
       7. The apparatus of claim 2 wherein said substrate support platen further comprises heating means for increasing the temperature of the first surface of said substrate support platen. 
     
     
       8. The apparatus of claim 2 wherein said retaining means comprises a substrate support housing that encloses cooling means for cooling the second surface of said substrate support platen. 
     
     
       9. The apparatus of claim 8 wherein said cooling means comprises a cooling plate having spring means to maintain contact between the cooling plate and the second surface of the substrate support platen. 
     
     
       10. The apparatus of claim 8 wherein said cooling means is a cooling coil that carries a heat transfer liquid. 
     
     
       11. The apparatus of claim 2 wherein said substrate support platen further comprises means, embedded within the substrate support platen, for electrostatically retaining a substrate proximate said first surface of said substrate support platen. 
     
     
       12. The apparatus of claim 2 further comprising means, imbedded within said substrate support platen, for monitoring a temperature of said substrate support platen. 
     
     
       13. The apparatus of claim 12 wherein said means for monitoring the temperature is a thermocouple.